JP6653390B2 - Condensate discharge device - Google Patents

Description

  The present invention relates to a condensate drain.

  A specific example of a condensate drain in a steam system environment that is used to allow the discharge of the condensed phase of a fluid while the condensate drain prevents the gas phase discharge of the same fluid is the vapor trap It is.

  It is well known to provide a steam plant for producing useful energy and distributing it in the form of steam to various industrial application points of use.

  The presence of excess condensate in the main steam plant typically acts as a barrier to heat transfer, causing "water hammer" damage and can even cause corrosion of the pipeline, Not desirable. Therefore, it is preferable to keep the steam in the steam plant as dry as possible. To accomplish this, condensate is typically discharged from the lowest point of the main plant pipeline via one or more discharge lines. In order to limit the loss of steam from the plant, each exhaust line is provided with a respective steam trap, which acts ideally on the condensate and at the same time prevents the escape of "live" steam.

  The presence of condensate in the main plant pipeline is typically undesirable, but because the hot condensate contains useful energy, in a typical steam plant, the discharge lines and steam traps are removed from the main plant. A larger condensate designed to discharge condensate (ideally not live steam) and recirculate the discharged condensate through a downstream boiler for subsequent use in the plant Form part of a recovery system. Thus, each discharge line is typically fed to a condensate return line that is fed sequentially to one or more downstream receiver tanks. The receiver tank typically functions as a temporary storage unit for the discharged condensate, which is pumped from the receiver tank to a downstream boiler feed tank as needed.

  Conventional steam traps are typically mechanical devices that automatically open to drain condensate under certain conditions. For example, a ball float trap operates based on the difference in density between vapor and condensate. Condensate reaching the trap raises the ball float and lifts the valve out of the seat to release the condensate. However, such mechanical traps are not suitable for operation over a fluctuating pressure range and cannot provide data on the condensate being discharged.

  The present invention aims to provide an improved condensate drain.

  According to a first aspect of the present invention, a valve for controlling discharge of condensate from a condensate discharge device and a collection volume for collecting condensate discharged through the valve are defined, A collection chamber configured to receive the flow of the multi-phase fluid upstream of the valve containing the condensed phase; sensor equipment for monitoring parameters related to the thermodynamic properties of the fluid upstream of the valve; A controller configured to monitor condensate recovery based on the parameters and control opening and closing of the valve to regulate condensate recovery upstream of the valve, the controller comprising a choke of vaporized liquid. A condensate drain is further provided, wherein the condensate drain is further configured to determine an amount of condensate drained from the collection volume using flow rate calculations for the drain flow.

  In one example, the condensate drain may be a steam trap. The condensate drain may have an inlet for receiving a flow of the multi-phase fluid, which may be vapor and condensate. The collection chamber may be connected to the inlet. The valve may be provided on a wall of the collection chamber. The sensor device may include a first sensor for determining a temperature of the steam at the inlet. The sensor device may include a second sensor for determining a temperature of the condensate in the collection volume. The controller may be connected to the first and second sensors and valves. The controller opens and closes the valve to maintain a difference between the temperature of the steam at the inlet and the temperature of the condensate in the collection volume determined at a predetermined subcooled set point using the first and second sensors. It may be configured to control.

  The thermodynamic properties of the fluid may be, for example, the phase, temperature or pressure of the fluid. The monitoring parameter for the thermodynamic parameter may be a function of the thermodynamic property. For example, pressure or temperature may be monitored to determine the thermodynamic properties of the temperature. In a further example, the resonant frequency of the flexible member may be monitored to determine the thermodynamic properties of the fluid phase.

  The collection chamber may be configured such that, in use, there is a boundary between the condensate collected in the collection chamber and the upstream gas phase. That is, the collection chamber may be defined such that the condensate collects adjacent the valve and the gas phase separates and is located upstream of the valve under gravity.

  Upstream to downstream (ie, the direction of flow or the direction of fluid flow) refers to the direction in which the condensate discharge device can receive fluid to flow through the collection chamber and be discharged through the valve. There may be. This may be in the direction from the collection chamber to the valve.

  The valve may be an electromagnetic valve having an open position and a closed position. The controller may control the operating time of the solenoid valve to regulate the condensate recovery upstream of the valve.

  The sensor device may include a phase sensor configured to determine a phase parameter that is a function of the phase of the fluid at a detection location in the collection chamber, and / or a combination of the condensate collected in the collection chamber with the gaseous phase upstream of the fluid. There may be a level sensor configured to determine a phase parameter that is a function of the location of the boundary between them. The controller may be configured to control the opening and closing of the valve based on the phase parameters so that a boundary between the collection chamber and the gas phase upstream of the fluid is maintained within a predetermined range in the collection chamber. . For example, the phase sensor may be a conductivity sensor, a resonance density sensor, a capacitance sensor, or a subcool monitoring sensor.

  An exemplary subcool monitoring sensor includes a first sensor for determining a temperature of a gas phase at a first upstream location (a first sensing location) of the collection chamber, and a second downstream location (a second sensing location) of the collection chamber. A second sensor for determining the temperature of the condensate collected in the collection chamber at the detection position) may be provided. The controller opens and closes the valve to maintain a difference between the temperature of the steam at the inlet and the temperature of the condensate at the collection volume determined using the first and second sensors at a predetermined subcooled set point. It may be configured to control.

  The sensor device may be configured to monitor a phase parameter for a phase of the fluid upstream of the valve. For example, the phase parameter may be a function of the phase of the fluid at a location corresponding to the sensor (detection location), or may be a function of the location of the boundary between the two phases.

  The sensor device may include a level sensor configured to monitor a phase parameter relating to a location of a boundary between the condensate collected in the collection chamber and a gaseous phase upstream of the fluid. The phase parameter may be a function of the location of the boundary between the condensate collected in the collection chamber and the gas phase upstream of the fluid. The location of the boundary relates to the phase of the fluid at a location on either side of the boundary. For example, based on the location of the boundary, it may be determined that the phase of the fluid below the location of the boundary is a liquid while the phase of the fluid above the location of the boundary is a gas.

  The sensor device can include a float received in the collection chamber and a sensor for determining a phase parameter that is a function of the position of the float. For example, the float may be a metal chamber and the sensor may be configured to monitor a parameter that is a function of the position of the float in the collection chamber. For example, the metal chamber may include a permanent magnet, and the sensor may be a magnetostrictive sensor that produces an output signal corresponding to the magnetostrictive effect of a float (or its permanent magnet) on the sensor.

  The sensor device may include a phase sensor configured to monitor a phase parameter that is a function of the phase of the fluid at the detection location upstream of the valve.

  The phase sensor may be a conductivity sensor configured to monitor the conductivity of the fluid at the detection location. The phase sensor may be a capacitance sensor configured to monitor a parameter related to the dielectric properties of the fluid at the detection location.

  The phase sensor may be a resonant density sensor configured to monitor the density of the fluid at the detection location. The density sensor may include an element arranged to contact the fluid at the detection location, and an actuator for driving an oscillating movement of the element. The density sensor may be configured to determine a parameter that is a function of the density of the fluid, for example, the resonant frequency of vibration of the element.

  In some examples, there may be one phase sensor (eg, a single sensor) provided at the first detection location, and the controller may determine that the fluid at the first detection location is a gas phase or condensate May be configured to control the opening and closing of the valve based on whether the phase sensor indicates For example, the controller may be configured to open the valve or increase its operating cycle when it is determined that fluid is condensing at the first detection position, and the fluid may be condensed at the first detection position. The valve may be configured to close or reduce its operating cycle when it is determined that the position is in the gas phase. The controller may implement a delay between subsequent opening and closing actuations. The delay may be set to prevent all condensate from draining after the valve is opened and before it is closed. In such an example, the controller controls the opening and closing of the valve to maintain the boundary between the collected condensate and the gas phase substantially within a range having an upper limit corresponding to the first detection location. May be. At the first detection position, before the valve is opened or the operating cycle is increased (e.g., corresponding to some delay between valve detection and opening), after the fluid is determined to be condensate, Additional withdrawal of condensate may be provided, the range of which may extend beyond the first detection location, depending on the rate of condensate recovery and such delay prior to condensate drainage.

  In another example, there may be two phase sensors at the first and second detection locations spaced in the collection chamber, and the controller determines the boundary between the collected condensate substantially at the two detection locations. It may be configured to keep in the range between. Thus, the phase sensor may be used as one form of a level sensor configured to monitor when a boundary exceeds or falls below a level associated with a respective detection location. For example, any suitable combination of sensors may be a temperature sensor (temperatures below the saturation temperature may indicate the presence of condensate) or a phase sensor such as a capacity, conductivity or density sensor. Can be used at the detection position.

  The sensor device may further comprise a condensate temperature sensor for determining a temperature of the condensate in the collection volume. The controller may be configured to receive or determine the temperature of the upstream gas phase based on the output from the gas phase sensor upstream of the condensate temperature sensor. The controller may be configured to determine the subcool value as a temperature difference between the temperature of the upstream gas phase and the temperature of the condensate in the collection volume.

  The condensate drain may be connected to a fluid system comprising a gas phase sensor and configured to receive a multi-phase fluid from the fluid system.

  The condensate drain may be configured to be connected to the fluid system to receive the multi-phase fluid. The sensor device may further comprise a gas phase sensor for installation in the fluid system upstream of the condensate temperature sensor.

  The condensate drain may further include an inlet for receiving the flow of the multi-phase fluid. The sensor device may comprise a gas phase sensor upstream of the condensate temperature sensor, wherein the gas phase sensor may be configured to determine a temperature of the gas phase at one of an inlet, a collection chamber or a location therebetween. Good.

  The gas phase sensor may be a pressure sensor. The temperature of the gas phase at each location of the gas phase sensor may be derived based on predetermined data, such as a saturated steam table (eg, when the fluid is water). For example, such a derivation may be based on the assumption that the gas phase is saturated at each location.

  The gas phase sensor may be a temperature sensor.

  The controller may be configured to monitor the condensate recovery based on the subcool value. The controller may be configured to control the opening and closing of the valve while maintaining the subcool value at the subcool setting to adjust the collection of condensate upstream of the valve. The subcool setting value may be a predetermined setting value.

  The controller may have a user interface that allows a user to set subcool settings.

The value of F _LP used to calculate the amount of condensate may be based on operational cycle and subcooled value.

Controller at subcooling set value, if it is configured to maintain the subcooling value, the subcooling value and the subcooling set value may correspond to each other during use, the value of F _LP is subcooled set in the calculation of F _LP The value may be used to be based on the subcool value.

The value of F _LP used to calculate the amount of condensate may be based on the ratio of the operating cycle (DC) for subcooling value (SC).

  Constants A and B may be set to different values for different pressure zones.

  The controller may be a PID controller. That is, the recovery of the condensate upstream of the valve may be adjusted by PID control.

The controller is:
The condensate discharge path being cold when it is determined that the temperature of the gas phase (eg, the vapor temperature at the inlet) and the temperature of the condensate in the collection volume are lower than a predetermined value for a predetermined period;
Not opening the valve if the temperature of the gas phase and the temperature of the condensate in the recovery volume are substantially equal to each other for a predetermined period of time, both above a predetermined value;
Not closing the valve when the temperature of the gas phase and the temperature of the condensate in the recovery volume are both substantially equal to each other below a predetermined value for a predetermined period of time;
If the output of the first sensor is an open circuit, the first sensor has failed;
If the output of the second sensor is an open circuit, the second sensor has failed;
If the temperature difference between the gas phase and the condensate in the recovery volume exceeds the maximum subcool value for a predetermined period, the condensate discharge path is submerged;
May be configured to determine and output a user notification confirming the existence of one or more of the conditions. The temperature of the gas phase may be measured by a condensate temperature sensor or a gas phase sensor upstream of the valve, for example in a flow system to which a condensate discharge device is connected, or in a collection chamber or between them. It may be located at the entrance to the collection chamber, which is within range.

  Cooling fins may be provided on the outer surface of the collection chamber.

  The fluid may be water, the gas phase may be steam, and the condensed phase may be liquid water.

  According to a second aspect of the present invention, an inlet is provided for receiving a stream of vapor and condensate, and an inlet for receiving vapor and condensate and defining a collection volume in which the vapor and condensate are separated from one another. A connected collection chamber, a valve provided on the wall of the collection chamber, a first sensor for measuring the temperature of the vapor at the inlet, a second sensor for measuring the temperature of the condensate at the collection volume, A controller connected to the first and second sensors and the valve for controlling opening and closing of the valve to determine the temperature of the steam at the inlet and the set value of the predetermined subcool value using the first and second sensors; A controller configured to maintain a difference between the temperature of the condensate in the collection volume to be removed and the controller. That the flow rate calculation for choked flow of liquid with further configured to determine the amount of condensate being discharged from the collection volume, steam trap is provided.

  The valve may be an electromagnetic valve having an open position and a closed position, and the controller may control the operation time of the electromagnetic valve to maintain a temperature difference at a set value of the subcool value.

The value of F _LP used to calculate the amount of condensate may be based on operational cycle and a predetermined subcooled value.

The value of F _LP used to calculate the amount of condensate may be based on the ratio of the operating cycle (DC) for subcooling value (SC).

  Constants A and B may be set to different values for different pressure zones.

  The first sensor may be a pressure sensor, and the temperature of the steam at the inlet may be derived based on a saturated steam table.

  The first sensor may be a temperature sensor.

  The controller may be a PID controller.

  The controller may have a user interface that allows a user to set a set value of the subcool value.

The controller is:
The steam trap is cold when it is determined that the temperature of the vapor at the inlet and the temperature of the condensate at the recovery volume are lower than a predetermined value for a predetermined period of time;
Not opening the valve when the temperature of the vapor at the inlet and the temperature of the condensate at the recovery volume are substantially equal to each other over a predetermined period of time, above a predetermined value;
Not closing the valve when the temperature of the vapor at the inlet and the temperature of the condensate at the recovery volume are both below a predetermined value and substantially equal to each other for a predetermined period of time;
If the output of the first sensor is an open circuit, the first sensor has failed;
If the output of the second sensor is an open circuit, the second sensor has failed;
The steam trap is submerged if the temperature difference between the vapor at the inlet and the condensate at the recovery volume exceeds the maximum subcool value for a predetermined period of time;
May be configured to determine and output a user notification confirming the existence of one or more of the conditions.

  Cooling fins may be provided on the outer surface of the collection chamber.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention and to show more clearly how it may be implemented, reference is made to the accompanying drawings by way of example.
1 is a schematic diagram of an exemplary flow network with a condensate drain. FIG. 2 is a schematic view of a condensate discharge passage shown in FIG. 5 is a graph showing the correlation between calculated and measured flow values. For against the operating cycle to a pressure of 2 bar is a graph showing the value of F _LP. For 4 bar operating cycle against the pressure of a graph showing the value of F _LP. 5 is a graph showing the correlation between the calculated flow and the measured value of the corrected _FLP . 1 is a schematic diagram of an exemplary flow network with a condensate drain according to one embodiment of the present invention. 5 shows another example of the condensate discharge path. 5 shows another example of the condensate discharge path. 5 shows another example of the condensate discharge path.

  FIG. 1 shows a portion of an exemplary flow network 10 that includes a flow system 100, a condensate drain 200, and a condensate return line 30. The flow system 100 includes a fluid supply line 102, a heat exchanger 104, a fluid return line 106, and a condensate discharge line 108. The flow system 100 may be for conveying any working fluid, such as a refrigerant or water. In this example, heat exchanger 104 is configured to receive gaseous fluid from fluid supply line 102 at the top of the heat transfer chamber and exhaust gaseous fluid from moving body return line 106 from the bottom of the heat transfer chamber. Define the transfer chamber.

  The condensate drain line 108 is connected to the heat exchanger 104 at the bottom of the heat exchanger for receiving gaseous and / or liquid fluid from the heat exchanger 104.

  In one example, flow system 100 carries steam as a working fluid for heat transfer in heat exchanger 104. In use, the fluid supply line 102 carries saturated steam to the heat exchanger 104. Heat may be transferred from the steam in heat exchanger 104 such that a portion of the steam condenses. Some of the uncondensed vapor exits heat exchanger 104 via fluid return line 106. The condensate falls to the lower part of the heat exchanger 104 to be discharged from the heat exchanger 104 via the condensate discharge line 108.

  The condensate discharge line 108 is connected to a condensate discharge device 200 configured to receive the condensate and control its discharge to the condensate return line 30. For example, condensate return line 30 may form part of a condensate return system configured to recover condensate from, for example, flow system 100 for recovering heat from the condensate.

  As shown in FIG. 1, the condensate discharge device 200 includes a valve 202 for controlling the discharge of the condensate to the condensate return line 30 and a condensate 250 received from the condensate discharge line 108. A collection volume 204 upstream of the valve 202.

  In this example, the collection volume 204 of FIG. 1 is defined by a collection chamber 206 schematically shown as having a larger diameter than the condensate drain line 108. However, the collection chamber 206 and the collection volume may be of any shape, for example, the collection chamber may be defined by a section of tubing.

  The condensate drain device 200 further comprises sensor equipment for monitoring parameters related to the thermodynamic properties of the fluid upstream of the valve 202. As described with reference to each of the exemplary condensate drains described with reference to FIGS. 2 and 8-10, various configurations of the sensor device may be configured to include thermodynamics, such as temperature and phase. It may be used to monitor parameters related to statistical characteristics. In this example, the sensor device includes a first (or upstream) sensor 212 and a second (or downstream) sensor 214 located within the collection chamber 206, as described in detail below with reference to FIG. Prepare.

  Condensate drain 200 monitors condensate recovery based on the monitored parameters and opens and closes valve 202 to regulate condensate recovery upstream of valve 202, as described in more detail below. Further comprising a controller 230 configured to control

  The controller 230 is further configured to determine an amount of condensate discharged from the collection volume 204, as described in more detail below.

  FIG. 2 shows an exemplary condensate drain 200 for use in the flow network 10 of FIG. The condensate discharge device 200 is configured to discharge the condensate while preventing discharge of the gas phase of the fluid. In this example, the condensate drain may be referred to as a vapor trap or "trap" because the gas phase is vapor.

  The exemplary condensate drain 200 includes a collection chamber 206 having an inlet 205 for receiving vapor and condensate (ie, gaseous and condensed phases of fluid) streams. Collection chamber 206 defines a collection volume 204 in which the vapor and condensate 250 are separated from each other.

  In this example, the condensate discharge device 200 discharges the condensate based on a subcool value determined as the temperature difference between the gas phase received through the inlet 205 and the condensed phase collected in the chamber 206. Configured to control. The sensor device includes a first (or upstream) sensor 212 disposed in the inlet 205 and detecting the temperature of the vapor and condensate flowing into the chamber 206. The first sensor 212 may be a pressure sensor or a temperature sensor. If a pressure sensor is used, the temperature of the steam at inlet 205 may be derived using a saturated steam pressure and temperature table.

  A second (or downstream) sensor 214 is located within the collection chamber 206 for detecting the temperature of the condensate in the chamber 206. The second sensor 214 is a temperature sensor and is disposed so as to be submerged in the condensed liquid collected in the chamber 206.

  In this example, the valve 202 is an electromagnetic valve disposed below the collection chamber 206. The valve 202 is disposed between the collection chamber 206 and the discharge line 203. The discharge line 203 may be connected to the condensate return line 30 of FIG. Valve 202 may be selectively opened to drain condensate from collection chamber 206 to drain line 203.

Controller 230 is connected to valve 202. In this example, the controller 212 is a PID controller. Controller 230 receives inputs from first and second sensors 212,214. The controller 230 has a user interface that allows the user to input a set temperature t _sp for the subcool amount in the condensate drain device 200. The subcool temperature (SC) is the difference between the vapor temperature at the inlet 205 (t ₁ ) determined by the first sensor 212 and the condensation temperature (t ₂ ) at the collection volume 204 determined by the second sensor 214. is there. The outer surface of the collection chamber 206 may be provided with cooling fins 207 to help achieve the desired subcool.

The PID controller 230 controls the operation of the valve 202 so as to maintain the subcool temperature at a desired set temperature (or “subcool set value”), that is, t ₁ −t ₂ = t _sp . The subcool temperature may be controlled by adjusting the residence time of the condensate in the collection volume 204. Specifically, the controller 230 modulates the opening and closing of the valve 202 by changing the operating cycle value (DC) of the valve. The operating cycle is expressed as a percentage and represents the percentage of time that the valve 202 is open. For example, the working cycle may be set to 1, 2, 3, 4, 5, 10, 25, 50, 75, or 100%. For valves with a cycle time of 8 seconds, the valve is opened for 0.08, 0.16, 0.24, 0.32, 0.4, 0.8, 2, 4, 6, and 8 seconds every cycle time You.

  The controller 230 is configured to use the flow rate calculation for the choked flow of the vaporized liquid to determine the amount of condensate discharged from the collection volume.

here,
C _v = valve flow coefficient N ₆ = 27.3kg / hr
F _f = liquid critical pressure factor F _LP = combination of pressure recovery of valve with fittings and pipe geometry element p ₁ = upstream pressure p _v = vapor pressure of liquid at inlet temperature ρ = specific weight (mass density) upstream Condition.

FIG. 3 shows the correlation between the value calculated using this equation and the actual measured value, with _FLP set to one. As shown, the data fit a regression line with an R-squared value of 0.9978 and an error of 1.5-8%.

When using an electromagnetic valve (or other intermittently opening valve), it has been found that the time required for the system to reach equilibrium when opening the valve is short. It is believed that there is a very short delay of 250-400 ms before the saturated liquid begins to boil at the solenoid valve opening in a controlled manner. Thus, solenoid valves have special advantages over positioning control valves, such as providing cost and tight prevention, but conducting for uninterrupted flow through known _Cv openings. Calculating the mass flow rate using the Mason-Naylan equation leads to less accurate results.

By using the value of F _LP-based operating cycle and subcooling value, it has been confirmed that may Masoneilan expression is modified for use with an electromagnetic valve.

  Constants A and B are set to different values for different steam pressures or pressure bands at inlet 205. The pressure of the steam at the inlet 205 may be measured or determined using the first sensor 212 or may be known as a steam system. Constants A and B can be derived empirically by testing over the full range of conditions, ie, pressure band, subcool, and operating cycle values.

4 and 5 show the value of F _LP for Active cycles in each 2 and 4 bar. As shown, the value of F _LP decreases as operating cycle is reduced. This is due to the difference between the electrical signal (eg, a control signal corresponding to the open state of the valve) and the actual valve movement. Specifically, if the electrical signal becomes too short, the valve will not be able to respond as well. Since pressure plays a role in the force required to open the valve, the relationship is different at different pressures, as shown in FIGS. Therefore, it is necessary to use different values of A and B for each pressure or pressure band.

Figure 6 shows the correlation between the calculated with F _LP, the actual measured values and calculated values using the modified Masoneilan expression as described above. As shown, the data fit a regression line with an improved R-squared value of 0.9998 and a smaller error of less than 2.5%. Therefore, the controller 230 can accurately determine the volume of the condensate discharged from the collection chamber 206.

  Controller 230 is further configured to provide user notifications, such as alarms or other warnings, regarding the status of condensate drain 200. For example, the controller may determine one or more of the following conditions listed in the table below.

  The above example is based on steam at a boiling point of 240 ° C. with a pressure of 32 bar and therefore a minimum subcool of 2 ° C. and a maximum subcool of 30 ° C.

  The controller 230 may communicate with the first and second sensors 212, 214 and the valve 202 via a wired or wireless connection. The controller 230 may be located remotely from the trap itself, and a single controller 16 may be used to control several traps as part of a condensate management system.

  Although the controller has been described as having a user interface for entering a set value for the subcool value, it may alternatively be set at the factory. This may be set remotely, for example by a controller for a flow network with a condensate drain 200.

  FIG. 7 shows a second exemplary flow network 12 comprising a flow system 100 as described above, a condensate drain 700 and a condensate return line 30 as described above.

  In this example, the condensate drain device 700 is similar to the device 200 described above with reference to FIGS. 1 and 2, but first, the collection chamber 706 is formed from a section of piping. As shown in FIG. 7, the collection chamber 706 is substantially the same diameter as the condensate discharge line 108 of the flow system 100. In this particular example, the collection chamber 706 is a separate section of tubing that, in use, is coupled to the condensate discharge line 108, for example, by a flange mounting arrangement. However, in other examples, the collection chamber 706 may be formed by a part of the condensate drain line. In yet another example, the flow system has a port (such as a heat exchanger 104, or a port for fluid supply or return lines 102, 106) for attaching a condensate drain, and the collection chamber 706 is connected to the flow system. It may be attached to the port such that there is no intermediate condensate drain line.

  As with the collection chamber 206 described above, the collection chamber 706 is configured to receive a multi-phase fluid including both a gas phase and a condensed phase, and the condensate received in the collection chamber 706 is separated into an upstream location. With the flowing gas phase, it is configured to collect in the collection chamber 706 adjacent to the valve. As will be appreciated from the above, the collection chamber 706 may be configured such that the valve 202 is located lower in the chamber 706, with the chamber moving in a direction having a downward component and in an upstream direction toward the valve. And along the downstream direction (i.e., from the flow system to the valve 202) and the action of gravity separates gas and liquid phases having different densities. Thus, there is a boundary between the condensed phase and the gas phase in use.

  As will be appreciated from the above, the condensate may continue to collect in the collection chamber 706 such that the boundary between the condensate and the gas phase rises. As shown in FIG. 7, the condensate continues to collect so that the condensate rises to the condensate discharge line and, in some instances, to other components of the flow system 100, such as the heat exchanger 104. Is also good.

  The condensate drainage device 700 of FIG. 7 differs from the device 200 described above with reference to FIG. In this example, the sensor device includes a first (or upstream) sensor 712 for determining the temperature of the gas phase separated from the collection chamber 706, and in this example is located on the heat exchanger 104.

  The sensor device further includes a second (or downstream) sensor 214 installed in the collection chamber 206 so as to be submerged below the condensate collected in the collection chamber 206 as described above.

  Despite the different arrangement of the first sensor 712, the condensate drain 700 controls the collection of condensate upstream of the valve 202 based on maintaining the subcool value at a predetermined subcool setting as described above. It is configured to In this example, the subcool value is the difference between the temperatures obtained using the first sensor 712 and the second sensor 714.

  By locating the first sensor 712 further upstream of the valve 202, especially outside of the condensate drain 700, but instead in the flow system 100, the flow network 12 allows more condensate to flow upstream of the valve. Can be operated to gather.

  In particular, during operation, the gas phase may be maintained at a saturation temperature for a given pressure, which may be substantially uniform in certain parts of the flow network, such as heat exchanger 104. Upon condensation, the condensate initially reaches a saturation temperature, but a temperature gradient that reduces the temperature between the condensate at the boundary between the condensate and the gas phase and the condensate adjacent to the valve 202 for discharge There may be.

  When the arrangement of the subcool monitoring sensor is used as described above, the collection of the condensed liquid may be controlled by setting the subcool set value. For example, at a low subcool set point (ie, when a low temperature difference is set), the subcool value may reach the set value when a relatively small amount of condensate collects upstream of valve 202, The same applies when the residence time of the condensate upstream is relatively short. The controller opens and closes the valve to regulate condensate recovery and keeps the subcool value at the set value, so a relatively low subcool value corresponds to a small steady volume of condensate collected upstream of the valve during operation May be.

  In contrast, by setting a larger subcool value, more condensate may be collected on average upstream of the valve and the residence time of the condensate may be longer. In some examples, setting a larger sub-cool setting may result in more efficient thermal operation of the flow network. In particular, less heat energy may be released from the flow system via the condensate discharge channel, as the temperature of the condensate prior to discharge may be lower. Thus, more heat energy may be retained in the flow system.

  In some examples, the first sensor for monitoring the temperature of the gas phase may be separated from the second sensor for monitoring the temperature of the collected condensate by an amount corresponding to the subcool setting. . For example, if the subcool setting is relatively low, or if there is significant cooling between the sensors (eg, due to external cooling fins), the sensors may be relatively close to each other. However, if the subcool setting is relatively high, condensate may be collected to the location of the first sensor, unless they are properly separated.

  In the example of FIG. 7, the sensor device of the condensate discharge device 700 includes a first sensor 712 installed in the flow system upstream of the collection chamber 706. In other examples, the condensate drain may not include such a first sensor 712, but is, for example, a temperature sensor in a flow system such as a heat exchanger to which a condensate drain may be connected. It may be configured to receive or determine the temperature of the upstream gas phase based on the output of a sensor of the flow system 100.

  FIG. 8 shows a further example of the condensate drain device 800. The condensate discharge device 800 is the same as the device 200 described above with reference to FIG.

  In this example, the sensor device includes a first (or upstream) sensor 812 located at a first (or upstream) detection position above the collection chamber 206 and a second (or downstream) detection position below the collection chamber 206. And a second (or downstream) sensor 814 disposed at The controller 230 controls the opening and closing of the valve 202 based on the outputs of the first and second sensors to adjust the collection of the condensate in the collection chamber 206. Are located at, or between, the two detection locations (ie, the first and second or upstream and downstream detection locations).

  In this example, the first and second sensors 812, 814 may be configured to monitor a phase parameter that is a function of the phase of the fluid at each detection location.

  In this particular example, first and second sensors 812, 814 are conductivity sensors. The conductivity sensor may monitor the conductivity of the medium in which they are located, for example, by applying a load between two electrodes extending into the medium. Because the different phases of the fluid typically have different conductivities, depending on the nature of the electrical conduction between the two electrodes, it can be determined whether the fluid is in a condensed or gas phase at each detection location. For example, each conductivity sensor can be configured to produce an output, such as the conductivity of the medium, the voltage drop between the electrodes, the apparent impedance through the medium, or the current flowing through the system, , A parameter that is a function of the conductivity of the medium.

  The controller 230 receives the output from the first and second sensors 812, 814 and operates the valve to maintain the boundary between the two detection locations or the condensate collected between them and the upstream gas phase. It is configured to control the opening and closing of 202. For example, the controller 230 may close the valve when the fluid is determined to be in the gas phase at the second sensing position (or when the phase parameter indicates that the fluid is in the gas phase), or May be configured to reduce the operating cycle. Similarly, the controller 230 may open a valve when the fluid is determined to be in the condensed phase at the first detection position (or when the phase parameter indicates that the fluid is in the condensed phase), or It may be configured to increase the operating cycle of the valve.

  As shown in FIG. 8, in this example, the sensor device further includes a condensate temperature sensor 802 in the collection chamber 206 that is located below the condensate collected during use. In this example, the condensate temperature sensor 802 is below the level of the second (downstream) sensor 814. The controller 230 is configured to use the condensate temperature sensor 802 to determine the temperature of the collected condensate. The condensate temperature may be used to derive a Mason-Naylan term to determine the amount of condensate discharged from the collection chamber.

  In a further example, the controller can be configured to receive or determine the temperature of the upstream gas phase, for example, based on an output from a gas phase sensor upstream of the condensate temperature sensor. For example, the gas phase sensor can be located in the collection chamber or upstream of the condensate drain. The temperature of the upstream gas phase may be predetermined, stored in the memory of the controller, or otherwise provided to the controller.

  In such an example, the controller may determine the subcool value as the temperature difference between the temperature of the upstream gas phase and the temperature of the condensate in the collection volume. The subcool value may be used in the Mason-Naylan evaluation as described above, even if the controller is not configured to control the opening and closing of the valve based on the subcool value.

  In a further example, the first and second sensors 812, 814 may be capacitive sensors configured to generate an output that is a function of the dielectric properties of the fluid at the first and second sensing locations. Such a capacitive sensor may have opposing plates located in the collection chamber at each detection location and produce an output that is a function of the dielectric properties of the fluid between them. The dielectric properties of the gaseous phase and the condensed phase can be different, and based on the output, it can be determined whether the fluid is in the condensed or gaseous phase at each sensing location.

  FIG. 9 illustrates a further exemplary condensate drain device 900 that is similar to the device 800 described above with respect to FIG. 8, but differs in the particular type of the first and second sensors 912, 914.

  In this example, the first (upstream) sensor 912 and the second (downstream) sensor 914 are density sensors configured to generate an output that is a function of the density of the fluid at each detection location. In this particular example, each sensor comprises a flexible member 916 extending into the collection volume 204 at a respective detection position, and an actuator configured to oscillate the flexible member 916. Such a resonance density sensor operates on the principle that the resonance frequency of vibration depends on the density of the fluid. Sensors 912, 914 are configured to vibrate flexible member 916 to find a resonance frequency and generate an output signal that encodes the frequency or related parameter. As in the example described above with reference to FIG. 8, the controller is configured to receive an output signal indicative of the phase of the fluid at each detection location and control the opening and closing of the valve 202 accordingly.

  In other examples, the first and second sensors may use a combination of different sensor types. For example, the first sensor may be a density sensor and the second sensor may be a conductivity sensor.

  FIG. 10 shows a further example of a condensate drain device 1000 similar to the device 800 described above with respect to FIG. 8, but with a different sensor device.

  In this example, the sensor device includes a level sensor configured to monitor a parameter related to the location of a boundary between the condensate collected in the collection chamber 206 and the upstream gas phase.

  In this example, the level sensor is a float 1002, such as a metal ball surrounding a sealed gas or vacuum, located within the collection chamber 206, which floats at the interface between the collected condensate and the upstream gas phase. Is provided. The level sensor further comprises a sensor 1004 for monitoring a parameter that is a function of the position of the float 1002 in the collection chamber (and thus of the interface). For example, float 1002 may include a permanent magnet, and sensor 1004 may be a magnetostrictive sensor configured to monitor magnetostrictive strain as a function of float 1002's relative position in chamber 206.

  For example, other types of level sensors such as magnetic, mechanical, or capacitive sensors may be used.

  Although the example of the present invention has been described with reference to an electromagnetic valve that opens intermittently according to the operating cycle, other intermittently opening valves may be used. For example, a diaphragm valve can be used. Further, such valves may be operated electrically, pneumatically or hydraulically.

  Although the invention has been described with reference to a solenoid valve or other intermittently opening valve, aspects may also be used with a positioning control valve or other type of throttle valve.

  For example, a positioning control valve or a throttle valve may be controllable to define a variable size aperture through the valve to meter flow therethrough.

Claims (15)

A valve (202) for controlling the discharge of the condensate (250) from the condensate discharge device (200, 700);
A collection volume (204) configured to receive a flow of the multi-phase fluid upstream of the valve (202) containing gas and condensed phases and for collecting condensate (250) discharged through the valve (202). A collection chamber (206, 706) defining
Sensor equipment for monitoring parameters related to the thermodynamic properties of the fluid upstream of the valve (202);
A controller (230) configured to monitor condensate (250) recovery based on the monitored parameters and control opening and closing of the valve (202) to regulate condensate recovery upstream of the valve; ,
The controller (230) is further configured to determine an amount of condensate discharged from the recovery volume (204) using a flow rate calculation for a choked flow of the vaporized liquid. , Condensate discharge device (200, 700, 800, 900, 1000). The controller (230) controls the amount of condensate (250) discharged from the recovery volume (204).
Or using an equation derived from it,
Where C _v is the valve flow coefficient, N ₆ is 27.3 kg / hr, F _f is the liquid critical pressure factor, F _LP is the combination of pressure recovery and pipe geometry elements of the valve with fittings, and p ₁ is upstream Pressure, p _v is the vapor pressure of the liquid at the inlet temperature, and ρ is the upstream condition of the specific weight (mass density),
The condensate discharge device according to claim 1.   The valve (202) is an electromagnetic valve having an open position and a closed position, and the controller (230) controls the operating time of the electromagnetic valve to adjust the collection of condensate upstream of the valve (202). The condensate discharge device according to claim 1, wherein the condensate discharge device is controlled. A phase sensor configured to determine a phase parameter that is a function of a phase of the fluid at a detection location in the collection chamber (204);
And / or a level sensor configured to determine a phase parameter that is a function of the location of a boundary between the condensate (250) collected in the collection chamber (206, 706) and the gas phase upstream of the fluid. With
The controller (230) determines that the position of the boundary between the condensate (250) collected in the collection chamber (206) and the gas phase upstream of the fluid is within a predetermined range in the collection chamber (206, 706). A condensate discharge device according to any one of the preceding claims, configured to control the opening and closing of the valve (202) based on a phase parameter in order to be maintained.   5. The sensor device according to claim 1, wherein the sensor device further comprises a condensate temperature sensor for determining a temperature of the condensate in the recovery volume. 6. Condensate drain. The controller (230) is configured to receive or determine an upstream gas phase temperature based on an output from a gas phase sensor upstream of the condensate temperature sensor;
The condensate discharge of claim 5, wherein the controller (230) is configured to determine a subcool value as a temperature difference between an upstream gas phase temperature and a condensate temperature in the recovery volume. apparatus. The controller (230) is configured to monitor recovery of the condensate (250) based on the subcool value;
The controller (230) controls the opening and closing of the valve (202) while maintaining the subcool value at a subcool set value so as to adjust the recovery of the condensate (250) upstream of the valve (202). 7. The condensate drainage device according to claim 6, wherein The value of F _LP used to calculate the amount of condensate (250), based on the operating cycle and the subcooling value,
The operating cycle is the percentage of time that the valve is open,
Optionally, the value of F _LP used to calculate the amount of condensate (250) is based on the ratio of the operating cycle for the subcooling value (SC) (DC), according to claim 6 or claim 7 Condensate drain. A steam trap,
An inlet (205) for receiving vapor and condensate streams;
A collection chamber (206, 706) connected to said inlet (205) for receiving vapor and condensate (250) and defining a collection volume (204) where the vapor and condensate are separated from each other by gravity;
A valve (202) provided on a wall of the collection chamber (206, 706);
A first sensor for determining a temperature of the steam at the inlet;
A second sensor for determining the temperature of the condensate (250) in the recovery volume (204);
The first sensor and the second sensor are connected to the valve (202) and the temperature of the vapor at the inlet (205) and the subcool value are the temperature of the upstream gas phase and the condensate ( 250), wherein the condensate (250) in the collection volume (204) is determined using a first and second sensor according to a set value of a predetermined subcool value. ) A controller (230) configured to maintain a difference from the temperature of
The controller (230) is further configured to determine an amount of condensate (250) discharged from the recovery volume (204) using a flow rate calculation for a choked flow of the vaporized liquid. , Steam trap. The controller (230) controls the amount of condensate (250) discharged from the recovery volume (204).
Or using an equation derived from it,
C _v is the valve flow coefficient, N ₆ is 27.3 kg / hr, F _f is the liquid critical pressure factor, F _LP is the combination of pressure recovery and pipe geometry elements of the valve with fittings, p ₁ is the upstream pressure, p ₁ The steam trap according to claim 9, wherein _v is the vapor pressure of the liquid at the inlet temperature, and ρ is the upstream condition of the specific weight (mass density).   The valve (202) is an electromagnetic valve having an open position and a closed position, and the controller (230) controls the operation time of the electromagnetic valve to maintain a temperature difference at the set value of the subcool value. A steam trap according to claim 10. The value of F _LP used to calculate the amount of condensate (250), based on the operation cycle and a predetermined said subcooled value,
The operating cycle is the percentage of time that the valve (202) is open;
Optionally, the value of F _LP used to calculate the amount of condensate (250) is based on the ratio of the operating cycle (DC) with respect to the subcool value (SC), the steam trap according to claim 11.   13. The method according to claim 9, wherein the first sensor is a pressure sensor, and the temperature of the steam at the inlet is derived based on a saturated steam table, or the first sensor is a temperature sensor. Steam trap according to the item.   14. The steam trap according to any one of claims 9 to 13, wherein the controller (230) has a user interface that allows a user to set a set value of the subcool value. The controller (230) comprises:
The steam trap is cold when it is determined that the temperature of the vapor at the inlet (205) and the temperature of the condensate (250) at the recovery volume (204) are lower than a predetermined value for a predetermined period;
The valve (202) when the temperature of the vapor at the inlet (205) and the temperature of the condensate (250) at the recovery volume (204) are substantially equal to each other over a predetermined period of time, both above a predetermined value. Not open
The valve (202) when the temperature of the vapor at the inlet (205) and the temperature of the condensate (250) at the recovery volume (204) are substantially equal to each other below a predetermined value for a predetermined period of time. Not closed,
If the output of the first sensor is an open circuit, the first sensor has failed;
If the output of the second sensor is an open circuit, the second sensor has failed;
A steam trap submerged if the temperature difference between the vapor at the inlet (205) and the condensate (250) at the recovery volume (204) exceeds a maximum subcool value for a predetermined period of time;
15. The steam trap according to any one of claims 9 to 14, wherein the steam trap is configured to determine and output a user notification confirming the presence of one or more of the following conditions: